1. Field of the Invention
The present invention is related to information handling systems, and more specifically, to external power adapters for the information handling systems.
2. Background of the Related Technology
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes, thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems, e.g., computer, personal computer workstation, portable computer, computer server, print server, network router, network hub, network switch, storage area network disk array, RAID disk system and telecommunications switch.
Use of information handling systems in the office and at home have become ubiquitous and are rapidly becoming transparent to users of these information handling systems. More and more information handling systems are being deployed, and the capabilities and sophistication of these information systems have greatly increased in the last few years. With increased numbers, capabilities and sophistication, the electrical power required by these information systems has significantly increased. However, the full capabilities of the information handling systems may only be utilized a very small percentage of the total time that the systems are energized.
There is a long felt need in the information handling system technologies, e.g., computer industry, to have systems that consume one watt or less of power when they are in a standby or shutdown state. This is especially important to government entities and companies having large numbers of these systems, e.g., Department of Energy (DOE) Federal Energy Management Program (FEMP). Newer information handling systems have added hardware and firmware that allow turn off of various subsystems, e.g., onboard network interface controller (NIC) when going into a standby or shutdown state. Much of the future purchasing of new equipment quotations will favor low standby power consumption equipment.
New power saving technologies are being implemented in the latest information handling systems, e.g., instantly available personal computers (IAPCs). The Advanced Configuration and Power Interface (ACPI) specification provides a platform-independent, industry-standard approach to operating-system-based power management. The ACPI specification is a key constituent in Operating System Directed Power Management (OSPM). OSPM and ACPI may apply to all classes of information handling systems, e.g., computers, including handheld, notebook, desktop, servers, etc.
Many of these information handling systems use external power adapters, e.g., an external single output power converter, to reduce size, weight, cost and heat generation, and to add more flexibility in adapting to different voltages and electric receptacle configurations in various countries throughout the world.
There is a need for the single output power converter, e.g., having a 150 watt capacity, convection cooled, enclosed in a plastic box (e.g., dimensions of about 170×85×40 mm), and meeting the FEMP standards. However, in a single output power converter, rated for 150 watts of output power, it is difficult to have low enough overhead power consumption during light loading conditions and meet thermal requirements under full load conditions. The power consumption during minimum load conditions needs to comply with the FEMP, e.g., having a standby power draw of one watt or less. Current cost effective single output power supply topologies have difficulty minimizing the FEMP mandated low operating power requirements and still be able to meet all thermal dissipation requirements under full load conditions when using only convection cooling and being enclosed in a plastic box having, for example, the aforementioned dimensions.
On multiple output power supplies, the FEMP requirements have been addressed by having a separate standby power converter normally referred as the +5V standby or flee power. In the case of a single output supply, low-power control circuitry has been used. As the output power increases the minimum operating power required has increased to the point that exceeds the FEMP one watt limit.
Therefore, a problem exists, and a solution is required so as to meet energy saving standby requirements in an external power converter without exceeding power dissipation capabilities of the power converter components.